Väätäinen was coached by Paavo Meskus from 1963 until Meskus death in 1968. However, Väätäinen was pretty independent and planned his training mostly by himself.[6] He was also interested about the altitude training as early as in the winter of 1966-67 when he spent seven months in Alamosa as a student.[7]

In December 1969 Väätäinen stayed in Frankfurt on his trip to São Paulo. His foot slipped on the snowy road and Achilles tendon was injured. Anyway, he finished Saint Silvester Road Race being 26th. As his original intention was to continue training in Brazil after the race, he decided to stay in Penedo, Itatiaia. Because of the injury, his training was reduced until March 1970. However, in April 1970 he ran 1100 km.[8]

In 1970 Väätäinen improved his personal bests: 5000 metres in 13:43.2 and 10,000 metres in 28:19.6. After the season, the injured Achilles tendon was operated.[10]

The European Championships 10,000 meters final was held on 10 August. The race is regarded by many as one of the greatest distance races of all time. In front of a highly excited Finnish crowd Väätäinen was in a group of six runners at the final bell following David Bedford, who had led from the start. Väätäinen and Jürgen Haase both kicked past Bedford in a thrilling last lap "burn-up" bringing the crowd to its feet as they battled neck and neck to the line with Väätainen just edging out Haase in the new Finnish record time 27:52.78. Väätäinen ran last 400 metres in 53.8 seconds.[4]

The 5000 metres final was held four days later. Väätäinen won this event as well, beating Jean Wadoux and Harald Norpoth in the new Finnish record 13:32.8. This race also came down to a fast last lap, with Väätäinen's blazing the last 400 meters in 53.0 seconds.[4]

In the Track & Field News annual world ranking Väätäinen was ranked first both at 5000 and 10,000 metres.

In winter of 1971-72 Väätäinen trained at high altitude in Nairobi. In summer 1972 he suffered from Sciatica. At the Olympics in Munich he qualified for the 5000 meters final, but disappointed with a 13th place finish. However, only three days later in Rome Väätäinen improved his personal best at 5000 metres to 13:28.4. On the following day he ran 13:35.4 in Helsinki, placing third in the same race that Lasse Virén set a new World record 13:16.4. Väätäinen ended his athletics career after the season, attempting to come back in 1974 but unsuccessfully.[4]

By his education Väätäinen is a primary school teacher. However, he has not worked in the profession after the 1960s. During the years, Väätäinen has worked as a coach, being especially successful in the field racewalking. He has coached, for example, Reima Salonen and Sari Essayah. Väätäinen served as a head coach of long-distance runners at the Finnish Athletics Association in 1988-90. In the 2000s Väätäinen has worked as a painter.[1][3] In 2007 he was a candidate at the Finnish parliamentary election but was not elected. In 2011 he ran again and this time was elected as a candidate of the Finns Party. He did not seek re-election in 2015.